End cap for segmented stator

Abstract

A stator for an electromagnetic machine includes a plurality of discrete and individually wound stator segments having end caps positioned on the segments. The end caps have legs for positioning the end cap on the segments with an interference fit. The end caps have angled surfaces to facilitate winding of wire on the segments. The end caps have male and female couplings that mate together to couple adjacent segments together. The end caps have fingers and slots for aligning the segments on substantially the same plane. The end caps have wire isolation features, including hooks, shelves and ledges, for separating the interconnect wires routed on the stator to electrically interconnect the segments. The segments include scalloped contours on their outer edges for draining oil, and the end caps have passages for draining oil.

What is claimed is: 
     
       1. An end cap of an electromagnetic machine having a stator with a plurality of adjacent segments, the end cap including a body portion configured for positioning on a yoke portion of one of the adjacent segments, the body portion having first and second ends defining slots configured for engagement by a clip having a first portion for fitting in one of the slots and a second portion for fitting in one of the slots of an adjacent like end cap. 
     
     
       2. An end cap of an electromagnetic machine having a stator with a plurality of adjacent segments, each segment having a surface on which the end cap is positionable, the end cap including a body portion configured for positioning on a yoke portion of one of the adjacent segments, the body portion having first and second ends and first and second snap couplings on the first and second ends, respectively, the first and second snap couplings configured to snap couple to ends on adjacent end caps to substantially interlock and hold the adjacent segments together, a slot defined in the first end and having an open side for exposing the surface of the segment, and a finger extending from the second end and having a side substantially positionable on the same plane as the surface of the segment, wherein the finger fits within the slot on an adjacent like end cap with the side of the finger positioned against the surface of the adjacent segment so that the surfaces of the adjacent segments lie substantially on the same plane. 
     
     
       3. An end cap of an electromagnetic machine having a stator with a plurality of adjacent segments, the end cap including a body portion configured for positioning on a yoke portion of one of the adjacent segments, the body portion having first and second ends and first and second snap couplings on the first and second ends, respectively, the first and second snap couplings configured to snap couple to ends on adjacent end caps to substantially interlock and hold the adjacent segments together, the first snap coupling including a male member configured for positioning adjacent a slotted end of the segment, and the second snap coupling including a female member configured for positioning adjacent a ridged end of the segment. 
     
     
       4. An end cap of an electromagnetic machine having a stator with a plurality of adjacent segments, the end cap including a body portion configured for positioning on a yoke portion of one of the adjacent segments, the body portion having first and second ends and first and second snap couplings on the first and second ends, respectively, the first and second snap couplings configured to snap couple to ends on adjacent end caps to substantially interlock and hold the adjacent segments together, the first snap coupling including a male member and the second snap coupling including a female member, the male member including a bifurcate catch extending from the first end of the body portion for snap fitting in the female member of a like adjacent end cap. 
     
     
       5. The end cap of  claim 4 , wherein the female member includes a snap slot defined in the second end. 
     
     
       6. The end cap of  claim 4 , wherein the first snap coupling adjustably couples with the second snap coupling of a like adjacent end cap for adjusting alignment between the adjacent end caps. 
     
     
       7. An end cap for an electromagnetic machine having a stator, the stator having a plurality of adjacent segments, each segment having a segment surface, the end cap comprising:
 a body having a body surface configured for positioning against the segment surface of one of the segments such that the body surface and the segment surface lie on substantially the same plane, 
 wherein a portion of the body surface is positionable against the surface of an adjacent segment for aligning adjacent segments in a direction generally parallel to a central axis of the stator such that the surfaces of the adjacent segments lie substantially on the same plane. 
 
     
     
       8. The end cap of  claim 7 , wherein the portion of the body surface includes a finger extending from a first end of the body. 
     
     
       9. The end cap of  claim 8 , wherein the body includes a slot defined in a second end of the body, the slot having an open side for exposing the surface of the segment, the slot configured for receiving the finger of the adjacent end cap on the adjacent segment. 
     
     
       10. The end cap of  claim 8 , wherein the finger is positionable adjacent a ridged end of the segment, and wherein the slot is positionable adjacent a slotted end of the segment. 
     
     
       11. The end cap of  claim 8 , wherein the body further comprises:
 a female coupling on the first end of the body adjacent the finger; and 
 a male coupling on the second end of the body adjacent the slot, 
 wherein the male and female couplings on the adjacent end caps mate with one another to substantially hold the adjacent segments together. 
 
     
     
       12. The end cap of  claim 11 , wherein the male member includes a bifurcate catch extending from the first end and is configured for snap fitting in the female member of an adjacent like end cap. 
     
     
       13. The end cap of  claim 11 , wherein the female member includes a snap slot defined in the second end. 
     
     
       14. A stator for an electromagnetic machine, comprising:
 a plurality of adjacent segments of the stator, each segment having segment surface; and 
 a plurality of end caps, each end cap comprising:
 a body having a body surface positioned against the segment surface of one of the segments such that the body surface and the segment surface lie on substantially the same plane, 
 wherein a portion of the body surface is positioned against the surface of the adjacent segment for aligning adjacent segments in a direction generally parallel to a central axis of the stator such that the surfaces of the adjacent segments lie substantially on the same plane. 
 
 
     
     
       15. An electromagnetic machine, comprising:
 a stator having a plurality of adjacent segments, each segment having a segment surface; 
 a plurality of end caps, each end cap positioned against the segment surface of one of the adjacent segments and having first and second ends; and 
 means on the end caps for aligning the first and second ends of the adjacent end caps in a direction generally parallel to a central axis of the stator such that the segment surfaces of the adjacent segments lie on substantially the same plane. 
 
     
     
       16. A method of assembling a stator for an electromagnetic machine, the stator having a plurality of segments and a plurality of end caps, the method comprising the steps of:
 a) positioning an end cap on each of the segments, each end cap having a body portion for engaging a yoke portion of one of the segments, each body portion having opposite ends and snap couplings on the opposite ends;
 b) positioning ends of the segments adjacent one another; and 
 c) substantially interlocking and holding the ends of the adjacent segments together by snap coupling said ends of the adjacent end caps together. 
 
 wherein the step (a) comprises 
 positioning a surface of each end cap against a segment surface of each segment; and 
 substantially aligning the segment surfaces of the adjacent segments on substantially the same plane by fitting a portion of each end cap surface against the segment surface of at least one of the adjacent segments. 
 
     
     
       17. The method of  claim 16 , wherein the step (b) comprises the step of positioning a ridged end of one segment into a slotted end of the adjacent segment. 
     
     
       18. The method of  claim 16 , wherein the step (c) comprises the step of mating male and female snap couplings on the ends of the adjacent end caps. 
     
     
       19. The method of  claim 16 , wherein the step (c) comprises the step of permitting movement at the snap coupled ends of the adjacent end caps in a direction generally parallel to a central axis of the stator. 
     
     
       20. The method of  claim 16 , wherein the step (a) comprises the step of substantially retaining the end caps on the segments by engaging the end caps on the tooth portions with an interference fit. 
     
     
       21. A method of assembling a stator for an electromagnetic machine, the stator having a plurality of segments and a plurality of end caps, the method comprising the steps of:
 a) positioning an end cap on each of the segments, each end cap having a body portion for engaging a yoke portion of one of the segments, each body portion having opposite ends; 
 b) positioning ends of the segments adjacent one another; and 
 c) substantially holding the ends of the adjacent segments together by fitting clips in slots defined in the adjacent ends on the adjacent end caps. 
 
     
     
       22. A method of assembling a stator of an electromagnetic machine, the stator having a plurality of segments, a plurality of end caps, and wire, each segment having opposing surfaces, a yoke portion, a tooth portion, and a pole end, the method comprising the steps of:
 a) positioning the end caps on the opposing surfaces of the segments with the end caps substantially covering the yoke portions; 
 b) substantially retaining the end caps on the segments by engaging the end caps on the tooth portions with an interference fit; 
 c) winding the wire on the segments and the end caps; and 
 d) forming the segments into the stator including substantially aligning one of the opposing surfaces of each of the adjacent segments on substantially the same plane by positioning a portion of the surface on each of the end caps against the opposing surface of at least one of the adjacent segments.